Honeybees are disappearing in various regions around the world, causing biologists and environmentalists concern over what could happen if most of the pollinating insects die off. Beekeepers, who depend on the tiny flying insects to make their livings, are depending on healthy populations of bees to fly from their boxes this spring.

Each winter, large numbers of bees die off, leaving decimated populations as the weather begins to warm. Over the last several years, this annual winter culling has become more severe, in a mysterious process called colony collapse disorder (CCD). The winter of 2015-16 was especially hard on the flying insects.

"Nationwide, it's the worst in 10 years. I've had groups of bees where 40 to 60 percent of them have died over the winter, and I've had friends who lost 90 to 100 percent of their colonies," said David Bradshaw, a California beekeeper.

Bee colonies, both natural and artificial, are centered on a single queen, who lays eggs, and is attended by up to 30,000 other insects. These insects sell for about $35 each, and a large apiarist may require hundreds of queens for honey production.

Scientists are still uncertain what is causing CCD, although many people blame the tiny varroa mite. Others lay the blame on emerging diseases, or the use of pesticides composed of neonicotinoids.

In addition to the loss of honeybees from CCD, the ongoing droughts in California and elsewhere in the world are also contributing to the reduction in populations. Without water, farmers are choosing not to grow certain crops which bees depend on for nourishment.

"These problems, many of which honey bees might be able to survive if each were the only one, are often hitting in a wide variety of combinations, and weakening and killing honey bee colonies. CCD may even be a result of a combination of two or more of these factors and not necessarily the same factors in the same order in every instance," The United States Department of Agriculture (USDA) reports on their website.

More than one-third of all crops used by human beings depend on bees for pollination. Many people consume local honey, in an effort to take pollen from their area in their bodies. This is reported to relieve symptoms of allergies to vegetation.

This spring, beekeepers, honey-lovers, and people with allergies will all be hoping to see bees buzzing around their yards.